In order to analyze a circuit by using computers, it is necessary to describe the circuit in some way. In the case of digital circuits, this corresponds to numbering each node in the circuits and generating their coefficient matrixes. After the coefficient matrixes are obtained, the computable ordering of nodes can be decided for the time domain simulation. By such simulation, the impulse responses and the transfer function between arbitary nodes can be easily calculated.In order to obtain these coefficient matrixes, it may be suggested that they are made directly from the circuit. In this case, however, it is impossible to manage a large scale circuit by dividing it into some sub-circuits, and it is expected that there are careless mistakes of description. Considering these points, the enumerative description of each circuit element is generally used. This method is adopted in Spice which is a representative analyzing program of analog circuits. This description method is simple and p
… Morelain because it simply enumerates nodes' numbers to which elements are connected and the elements values. However, it costs the users much time to manage all of the nodes' numbers and the circuit parameters completely.In this paper, we propose a novel method to describe digital circuits as a kind of language instead of simply enumerating data of connections. By the proposed method, it is possible to describe a whole circuit as interconnections of a main circuit and some subcircuits, and to deal the main circuit as a main routine of ordinal procedural languages and each sub-circuit as a sub-routine. At that time, nodes in each sub-circuit can be named independently and numbered automatically by the system without users' management. In the proposed method, an effective description of circuits is expected by using a lot of instructions and recursive calls of sub-circuits.In the case of designing analog circuits, time varying elements are rarely used. On the contrary, in the case of digital circuits, the adaptive signal processing systems which vary the coefficients of multipliers can be easily constructed. For easy simulation of these adaptive circuits, independent management of the multiplier coefficients of each sub-circuit is available in the proposed description method. Less